Measles

n. pl. in form, but used as singular in senses 1, 2, & 3.
  1. (Med.) A contagious viral febrile disorder commencing with catarrhal symptoms, and marked by the appearance on the third day of an eruption of distinct red circular spots, which coalesce in a crescentic form, are slightly raised above the surface, and after the fourth day of the eruption gradually decline; rubeola. It is a common childhood disease.
  2. (Veter. Med.) A disease of cattle and swine in which the flesh is filled with the embryos of different varieties of the tapeworm.
  3. A disease of trees.
    4. German measles
    A mild contagious viral disease, which may cause birth defects if contracted by a pregnant woman during early pregnancy; also called rubella.